Picosecond = 10 ^ -12 seconds.
Zeptosecond = 10^ -18 seconsds
Petaseonds = 10^15 seconds
To express Picoseconds into any of other two, you have to divide 10^-12 by the power index of the one in question
1Picosecond : 10^-12 / 10^-18 = 10^ (-12- 18) = 10^ (-12+18)= 10^6 zeptoseconds
1Picosecond : 10^-12 / 10^15 = 10^ (-12-15) = 10^-27 Petaseconds.
1Picosecond = 10^6 zeptoseconds
1Picosecond = 10^-27 Petaseconds
